Hiroshi Shirota

E6201 [(3S,4R,5Z,8S,9S,11E)-14-(Ethylamino)-8, 9,16-trihydroxy-3,4-dimethyl-3,4,9,19-tetrahydro-1H-2-benzoxacyclotetradecine-1,7(8H)-dione], a Novel Kinase Inhibitor of Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Kinase (MEK)-1 and MEK Kinase-1: In Vitro Characterization of Its Anti-Inflammatory and Antihyperproliferative Activities

The goal of this study is to identify a novel inhibitor with anti-inflammatory and antiproliferative properties for the treatment of psoriasis. Compound f152A1 [(3S,5Z,8S,11E)-8,9,16-trihydroxy-14-methoxy-3-methyl-3,4,9,10-tetrahydro-1H-benzo[c][1]oxacyclotetradecine1,7(8H)-dione] was identified as the main active metabolite with strong inhibitory activity against tumor necrosis factor-α (TNFα) transcription in a fraction originated from the fermentation broth of the fungus Curvularia verruculosa. Although active in cell-based assays, f152A1 was unstable in plasma and liver microsome preparations, thus limiting its pharmaceutical utilization. To improve the metabolic properties of f152A1, a medicinal chemistry program was undertaken, resulting in the generation of over 400 analogs of f152A1. Eventually, E6201 [(3S,4R,5Z,8S,9S,11E)-14-(ethylamino)-8,9,16-trihydroxy-3,4-dimethyl-3,4,9,19-tetrahydro-1H-2-benzoxacyclotetradecine-1,7(8H)-dione] was identified as a promising analog in this series. In the present study, we characterized the in vitro activities of E6201 and discovered that the compound inhibits lipopolysaccharide-activated TNFα reporter activity in THP-1-33 cells with an IC50 value of 50 nM and selectively inhibits mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK)-1 and MEK kinase-1 in cell-free biochemical assays. In addition, E6201 showed inhibitory activity in several other cell-based systems: 1) phosphorylation of c-jun N-terminal kinase and p38 MAPKs; 2) nuclear factor-κB and activated protein-1 activation in various cell types; 3) interleukin (IL)-2 production from human lymphocytes; 4) hyperproliferation of human keratinocytes; 5) IL-8 production from human keratinocytes; and 6) proinflammatory cytokine production from human peripheral blood mononuclear cells. Based on the data presented here, E6201 may be beneficial for treatment of inflammatory and hyperproliferative diseases such as psoriasis through its anti-inflammatory activities on immune cells and antihyperproliferative activities on keratinocytes.

ER-34122, a novel dual 5-lipoxygenase/cyclooxygenase inhibitor with potent anti-inflammatory activity in an arachidonic acid-induced ear inflammation model.

Abstract. Objective and Design: To investigate the effect of ER-34122, a novel pyrazole derivative, on 5-lipoxygenase (LOX) and cyclooxygenase (COX) metabolite production in vitro, ex vivo and in vivo.¶Material: In vitro, lysate of rat basophilic leukemia cells, the microsome fraction of sheep seminal vesicles, human polymorphonuclear leukocytes, human synovial cells, and human monocytes. Ex vivo and in vivo, male Balb/c mice or SD rats.¶Treatment: In ex vivo study, ER-34122 (0.03-1 mg/kg) was orally administered 1 h before withdrawal of blood samples. In carrageenin-induced paw edema, ER-34122 (3–100 mg/kg) and indomethacin (1–10 mg/kg) were orally administered 1 h before carrageenin injection. In arachidonic acid-induced ear inflammation, ER-34122 (0.3–10 mg/kg), zileuton (10–100 mg/kg) and indomethacin (0.3-3 mg/kg) were orally administered 1 h before arachidonic acid application.¶Methods: 5-Hydroxyeicosatetraenoic acid and other eicosanoids were determined by using an HPLC method and enzyme immunoassay, respectively. Rat hind paw edema and mouse ear edema were assessed by measuring paw volume and ear thickness, respectively. Myeloperoxidase (MPO) activity and eicosanoid content of the ear tissue were also determined.¶Results: ER-34122 inhibited both LOX and COX product generation in vitro, and ex vivo. ER-34122 and indomethacin inhibited carrageenin-induced paw edema formation. In the arachidonic acid-induced ear inflammation, ER-34122 inhibited inflammatory responses (edema formation and MPO accumulation) as well as eicosanoids (LTB4, LTC4 and PGE2) generation. A representative LOX inhibitor, zileuton, also inhibited these inflammatory responses, while a COX inhibitor, indomethacin, did not suppress them though it completely inhibited PGE2 generation.¶Conclusions: The anti-inflammatory characteristics of ER-34122 are considered to be superior to those of COX inhibitors such as indomethacin, because in addition to its inhibitory activity on the COX pathway, ER-34122 inhibits LOX products generation, as revealed by the inhibition of edema formation or polymorphonuclear leukocyte infiltration in the arachidonic acid-induced ear inflammation model.

Discovery of anti-inflammatory clinical candidate E6201, inspired from resorcylic lactone LL-Z1640-2, III.

Inspired by natural product, LL-Z1640-2, clinical candidate, E6201 (22) was discovered in a medicinal chemistry effort through total synthesis. The modification on C14-position to N-alkyl substitution showed to be potent in vitro and orally active in vivo in anti-inflammatory assays.

Discovery of a potent, metabolically stabilized resorcylic lactone as an anti-inflammatory lead

With bioactivity-guided phenotype screenings, a potent anti-inflammatory compound f152A1 has been isolated, characterized and identified as the known natural product LL-Z1640-2. Metabolic instability precluded its use for the study on animal disease models. Via total synthesis, a potent, metabolically stabilized analog ER-803064 has been created; addition of the (S)-Me group at C4 onto f152A1 has resulted in a dramatic improvement on its metabolic stability, while preserving the anti-inflammatory activities.

E6201, a Novel Kinase Inhibitor of Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Kinase-1 and Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase Kinase Kinase-1: In Vivo Effects on Cutaneous Inflammatory Responses by Topical Administration

E6201 [(3S,4R,5Z,8S,9S,11E)-14-(ethylamino)-8,9,16-trihydroxy-3,4-dimethyl-3,4,9,10-tetrahydro-1H-2-benzoxacyclotetradecine-1,7(8H)-dione)] is a novel anti-inflammatory agent that has potent inhibitory effects on the production of proinflammatory cytokines from leukocytes and antiproliferative activity on keratinocytes. To characterize the in vivo pharmacological activity of E6201, topically administered E6201 was evaluated in several different animal models of dermatitis. E6201 formulated as an ointment or cream showed dose-dependent inhibition of croton oil-induced acute edema formation and neutrophil infiltration into mouse skin. In addition, E6201 cream inhibited the 1-fluoro-2,4-dinitrobenzene-induced contact hypersensitivity reaction mediated by T cells in mice. In this model, E6201 cream also suppressed the migration of neutrophils and lymphocytes into the inflammatory site. Pretreatment with E6201 cream attenuated phorbol-12 myristate 13-acetate-induced ornithine decarboxylase activity, a marker of proliferation in epidermis. Furthermore, E6201 ointment showed inhibitory effects on both mezerein-induced and interleukin (IL)-23-induced epidermal hyperplasia. E6201 also suppressed T cell receptor-stimulated IL-17 production from human T cells. These results indicate that topically administered E6201 may be a useful agent for the prevention and treatment of cutaneous inflammatory and hyperproliferative diseases such as psoriasis.

Discovery of an in vitro and in vivo potent resorcylic lactone analog of LL-Z1640-2 as anti-inflammatory lead, II

The potent in vitro lead compound, ER-803064 (2), a MEK1 and MEKK1 inhibitor inspired from natural product LL-Z1640-2 (f152A1), was further optimized to improve in vitro and in vivo potency. The modifications on C14 position led to discovery of the lead compounds 28 and 29, which regained full in vitro potency of f152A1 and showed higher in vivo potency by iv administration.

Stimulation of prostaglandin synthesis in cultured rat synovial cells by a factor derived from polymorphonuclear leukocytes

Stimulation of synovial cell prostaglandin production by a factor obtained from casein-induced peritoneal polymorphonuclear (PMN) cells has been investigated. Both the extract and short time cultured medium of rat peritoneal PMN cells stimulate prostaglandin (PG)E2 production as well as collagenase production in the culture of rat synovial cells. PGE2 production by the cells in the presence of the PMN factor is much faster (5 to 24 hr) than collagenase production (24 hr or later, Biomedical Res. 3, 506-516, 1982). This stimulating factor is confirmed to be derived from PMN cells, based on the purification of the cells from peritoneal exudate cells by the Ficoll-Urographin method. Elution profile of the factor on gel filtration has indicated that both PGE2 and collagenase productions by synovial cells are stimulated by the same effluent fractions corresponding to molecular weights of 15,000 - 20,000 daltons and 30,000 - 40,000 daltons. These results suggest that PMN cells are involved in PG production as well as collagenase production in the inflamed tissue by stimulating connective tissue cells such as synovial cells.

Effects of ER-34122, a novel dual 5-lipoxygenase/cyclooxygenase inhibitor, on indices of early articular lesion in MRL/MpJ-lpr/lpr mice

Abstract.Objective and Design: To investigate effects of ER-34122, a novel dual 5-lipoxygenase (LOX)/cyclooxygenase (COX) inhibitor, and indomethacin on progression of articular lesions in MRL/MpJ-lpr/lpr (MRL/l) mice.¶Material: 100 male MRL/l mice.¶Treatment: ER-34122 (1-100 mg/kg) and indomethacin (1 mg/kg) were orally administered once a day to MRL/l mice from 6 to 10 or 16 weeks old.¶Methods: Articular lesions were analyzed histopathologically in the early (10 weeks old) or late (16 weeks old) stages of MRL/l mice arthritis. Serum levels of rheumatoid factor were measured by using enzyme-linked immunosorbent assay.¶Results: Articular lesions in the late stage of MRL/l mice arthritis were characterized by cartilage degeneration and pannus formation which were severer than those in the early stage. Polymorphonuclear leukocyte (PMN) infiltration and subsynovial soft tissue edema were observed as characteristic lesions in the early stage. ER-34122 suppressed progression of PMN infiltration, subsynovial soft tissue edema and multiplication of synovial lining cells in the early stage of the arthritis, even though it had no significant effect on other indices of articular lesion, enlargement of lymph nodes and serum levels of rheumatoid factors. On indices of late articular lesion, ER-34122 had no significant beneficial effects. Neither in the early nor late stage, indomethacin, a COX inhibitor, had significant effect on the arthritis at the examined dose.¶Conclusions: These results disclosed that ER-34122, a dual LOX/COX inhibitor, has anti-inflammatory activity in the early stage of the spontaneous arthritis.

Inhibitory effect of indomethacin farnesil, a novel antiinflammatory prodrug, on carrageenin-induced inflammation in rats.

Antiinflammatory effects of indomethacin farnesil (IMF), a novel prodrug of indomethacin, was examined after both oral and local administration. In the air pouch carrageenin-induced inflammation, an oral dose of IMF exerted dose dependent inhibitory effects on the accumulation of inflammatory exudate fluid and the migration of leukocytes into the exudate. Both the increased vascular permeability and the prostaglandin E2 levels in the exudate fluid were reduced by IMF. Significant levels of free indomethacin were detected in the pouch fluid. In spite of the inability of IMF to inhibit prostaglandin synthesis in a cell free cyclooxygenase system, IMF injected locally inhibited carrageenin paw edema, and the inhibitory effect was comparable to that of indomethacin itself. When injected locally into the paw together with carrageenin,14C-IMF was effectively converted to its active metabolite, indomethacin. The indomethacin concentration in the paw tissue was comparable to that of indomethacin injected paws with the same molar dose of free indomethacin.

Inhibitory effects of E-5110 on interleukin-1 generation from human monocytes

Effects of E-5110, a novel non-steroidal antiinflammatory drug, on interleukin-1 (IL-1) generation from human monocytes were studiedin vitro. E-5110 reduced the amounts of extra- and intracellular IL-1 activity induced by lipopolysaccharide (LPS, 1 μg/ml) in a dose-dependent manner (1–10μM). E-5110 also inhibited the IL-1 generation induced by antigen-antibody complexes, opsonized zymosan and silica particles. It was suggested that the inhibition of IL-1 generation by E-5110 was independent of the inhibitory effects on arachidonate cyclooxygenase and/or lipoxygenase because indomethacin, piroxicam, BW755C and AA861 had no effects on IL-1 generation. Hydrocortisone (IC50:0.084 μM), aurothioglucose (11.5 μM) and lobenzarit (75.0 μM), which are clinically effective antirheumatic drugs, also inhibited IL-1 generation, like E-5110 (1.21 μM). It is expected that E-5110 will be superior to classical non-steroidal antiinflammatory drugs in medical treatment of rheumatoid arthritis.